1. Field of the Invention
The present invention relates to a motor driving device, more particularly to a motor driving device for making a current of a driving control signal of a carrier motor variable according to an ink consumption quantity in an inkjet printer.
2. Discussion of Related Art
A motor driving device exemplary of contemporary practice in the art for driving a carrier motor of an inkjet printer drives the carrier motor with a driving current by determining the driving current of the carrier motor on the basis of an ink quantity first stored within an ink cartridge regardless of an ink quantity stored within the ink cartridge for driving the carrier motor.
Accordingly, such a motor driving device exemplary of contemporary practice in the art can have problems relating to wasting electric power by consuming unnecessary energy for driving the motor according to the ink consumption, in that a driving current for driving the carrier motor is always constant, even though ink stored within the ink cartridge through use of the inkjet printer is consumed. Also, in that a load of the carrier being driven by the carrier motor is reduced as the ink is consumed, unnecessary noise in movement of a carrier can be caused due to unnecessary energy being consumed.
Accordingly, it is therefore an object of the present invention to provide a motor driving device capable of saving consumption of electric power and preventing unnecessary noise by making a driving current for the carrier of the inkjet printer variable according to an ink quantity stored within an ink cartridge.
In order to achieve the above and other objects of the present invention, a motor driving device according to the present invention includes: a detector of an ink consumption quantity outputting a comparative signal when a present ink quantity stored within the ink cartridge is less than the reference ink quantity through counting whether an ink drop signal is activated compared against a received reference signal indicating the reference ink quantity, the ink drop signal for producing an ink drop formed in at least one of a number of nozzles of the inkjet printer; a voltage generator for outputting a motor driving control voltage having a variable voltage according to whether the comparative signal is output from the detector, the voltage generator for receiving the comparative signal; and a motor controller for outputting a plurality of phase control signals each having associated therewith a different driving current for driving the carrier motor according to the motor driving control voltage received from the voltage generator and according to at least one of a first phase signal and a second phase signal for the driving current.
Also, the detector of an in consumption quantity preferably includes a counter for outputting a count signal to indicate a present ink quantity stored within the ink cartridge through counting each ink drop signal by receiving each ink drop signal producing a corresponding at least one ink drop, after checking whether the ink drop is formed in at least one of a number of nozzles of the inkjet printer; and a comparator for outputting a comparative signal if the count signal is smaller than the reference signal by receiving and comparing the count signal and the reference signal indicating the reference ink quantity.
Also, in the present invention the voltage generator preferably outputs a motor driving control voltage having a first voltage if the comparative signal is not output by the detector and having a second voltage smaller than the first voltage if the comparative signal is output by the detector.
Further, the voltage generator preferably includes a first resistance having one terminal connected to a first supply voltage and the other terminal for outputting a motor driving control voltage; a second resistance having one terminal for connection to the motor driving control voltage and the other terminal being connected to a second supply voltage through a switching member; a third resistance having one terminal for connection to the motor driving control voltage; and a switching member, through which the other terminal of the third resistance gets cut (or closed) or opened to the second supply voltage by the switching member becoming turned on or off according to whether the comparative signal is received by the switching member.
Moreover, the motor controller preferably outputs a plurality of phase control signals for the driving current for the carrier motor according to whether the motor driving control voltage has a first voltage for providing a larger driving current for the carrier motor than when the motor driving control voltage has a smaller second voltage than the first voltage, by receiving the motor driving control voltage and at least one of first and second phase signals for the driving current.
Further, the switching member preferably includes a transistor having an emitter, a base and a collector, in which the emitter is for connection to the second supply voltage and the base is for connection to receive the comparative signal and the collector is connected to the other terminal of the second resistance.
Also, the present invention provides a motor driving device for an ink jet printer that includes an inkjet printer head for reciprocating movement on a carrier, an ink storing vessel for reciprocating movement concurrently with the inkjet printer head and for connection with the inkjet printer head, a detecting means for sensing an amount of remaining ink in the ink storing vessel, a driving means for driving the inkjet printer head and the ink storing vessel for the reciprocating movement, and a power controller for changing the voltage supplied to the driving means according to a sensing result of the amount of the remaining ink in the ink storing vessel by the detecting means.